I have found an 1873 Springfield in my grandpas basement when I was doing some cleaning. The gun looks to be in excellent shape. My grandpa said he hasn't shot it in over 50 years. I did a very thorough cleaning and its load development time. I'm not familiar with this action or a 45-70 either which is what this is chambered in. I am debating on using some Trail Boss. Any load suggestions appreciated. CJ

The older 45-70 trapdoors can't hold the pressure that modern day firearms can. So if you reload for it be careful and make sure you use the right data for it!

most reloading manuals will a section of loads for the older rifles, possibly start with the minimual load

.... Good advice there. The Lyman manual will give you loading data for three different parameters..
(1) Older Trapdoor type guns
(2) Modern lever action rifles such as Marlin in 45/70
(3) Modern Falling block and Bolt actions such as Ruger, etc.

.... Use a little caution and common sense there. I do believe the "off the shelf" ammo by Remington that's out there today is only loaded to the specs for the early-type guns, such as what you're dealing with. It sure would be beneficial to you to have it thoroughly checked by a competent 'smith before you do anything, tho...

I am very aware they don't stand up to near the pressures of todays firearms. Thats why I am using Trail Boss. Its designed for reduced loads for older firearms. I have plenty of load data available from Hodgdon/IMR on the "cowboy loads". Mainly was just curious if anyone had used this powder in this same action/caliber combination and how the results were.